JOURNAL 
OF THE 
ASIATIC SOCIETY OF BENGAL. 
—*•©»«- 
Part II.— NATURAL SCIENCE. 
No. I.— 1891. 
I. — On certain Spiders which mimic Ants. — By Surgeon J. H. Tull 
Walsh, I. M. S. 
[Received 25th February ; read 4th March ] 
Whoever has studied the structure and habits of the various genera 
of the Formicidce must have been struck by the “ fitness ” which these 
little creatures possoss for “ the struggle for existence.” Even in those 
individuals with a rudimentary and useless sting there are still the 
powerful biting mandibles, the acid poison which can be ejected, often 
to a considerable distance, on to the enemy and various protective 
odours, such as those secreted by the anal glands of most of the Doli- 
choderidce. The pangolin and other ant-eaters certainly cause havoc 
among the ants who make their dwellings in the ground, but smaller 
animals and birds cannot attack ants with impunity, and it is noticeable 
that the ants most frequently mimicked live and feed on trees. Such 
being the case the ant is well protected, and any other creature that, 
by an accident of natural selection, resembled an ant in form and colour 
would have obtained an advantage through this resemblance, all uncon- 
scious as regards the individual but conscious, if one may use such an 
expression, in relation to the orderly complexity of nature. The ad- 
vantageous resemblance would, according to generally accepted laws, be 
transmitted and strengthened until the mimic reaped the full benefit 
accruing from its likeness to the ants among which it lived. Such 
instances of mimierv are seen among a certain sub-family of spiders, 
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